1. Field of the Invention
This invention relates to diagnosis of wireless communications, for example between an access point and a mobile station.
2. Related Art
Diagnosing wireless networks is substantially more difficult than diagnosing wired networks: Link layer losses are non-negligible. Link state and channel state are often different at distinct ends of a communication link, e.g., at distinct ends of a communication link between an access point (AP) and a mobile station (MS). User experience is often both location-dependent and time-dependent, with the effect of providing a substantial challenge in problem reproducibility. Moreover, there is substantial variability between distinct types of mobile stations, with the effect that interaction between access points and mobile stations can be quite dependent upon the type of mobile station, and even the application being used by the mobile station.
This has the effect that signal degradation and network coverage might occur as problems, but be difficult to diagnose as they might appear as network handoff problems or other mobility issues, or vice versa. Moreover, untethered mobile stations often cannot contemporaneously report problems they are then experiencing, with the effect that many network problems involve difficult attempts to reproduce the problem environment at a later time.
One known solution is to maintain an activity log of network traffic at each access point, or at a controller for the network, with the effect of allowing a network administrator to review, after the fact, possible anomalies that might indicate network trouble. While providing at least some information about the nature of network traffic, this approach has the drawback that it is essentially passive in nature, and lacks the ability to sufficiently model the end-user experience with the network.